Add a fuzzer for CPDF_HintTables.

testing/libfuzzer/BUILD.gn

Index: testing/libfuzzer/BUILD.gn
diff --git a/testing/libfuzzer/BUILD.gn b/testing/libfuzzer/BUILD.gn
index 718a1db3c0bf4afb386fe972012460a58cafbddd..811618d0891abf831505cdd09b990cd9d54f2409 100644
--- a/testing/libfuzzer/BUILD.gn
+++ b/testing/libfuzzer/BUILD.gn
@@ -183,3 +183,18 @@ source_set("pdf_psengine_fuzzer") {
     ":libfuzzer_config",
   ]
 }
+
+source_set("pdf_hint_table_fuzzer") {
+  testonly = true
+  sources = [
+    "pdf_hint_table_fuzzer.cc",
+  ]
+  deps = [
+    "//third_party/pdfium:pdfium",
+  ]
+  configs -= [ "//build/config/compiler:chromium_code" ]
+  configs += [
+    "//build/config/compiler:no_chromium_code",
+    ":libfuzzer_config",
+  ]
+}